BIOL 2021 Lecture Notes - Tight Junction, Transcellular Transport, Cell Adhesion
Document Summary
Chapter 19: cell junctions, adhesion and extracellular matrix. Used in connective tissue; matrix of fibrous polymers causes stress: cell-cell adhesion and cytoskeleton. Used in epithelial cells on basal lamina (thin ecm) Figure 19. 2: classification of junctions: anchoring junction. Seals up gaps between epithelial cells: channel forming junction. Links cytoplasm of neighbouring cells: signal relaying junction. Figure: a) sealing strands in tight junctions b) claudins in tight junctions. Figure: diagram of gap junction and em of gap junctions (freeze fraction) Channels allow small molecules to pass as if the cytoplasm of cells is connected (passive) Cells coupled metabolically and electrically (sharing between cells) Fig 19-37: neurons connected to gap junctions with fluorescent dye (a); shut gap junctions (b) can stop coupling. Fast response: coordinate contraction of muscles. Heart, smooth muscle: also used for metabolic coordination. Ion channels, signal receptors, regulatory proteins (kinases), docking proteins. Scaffold proteins (let other proteins stick to it)
